在数组、列表等上使用 foreach 时的排序顺序

本文介绍了在数组、列表等上使用 foreach 时的排序顺序的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 29岁程序员，3月因学历无情被辞！ 当使用foreach遍历一个数组时，是否有任何保证元素返回的顺序是array[0], array[1], array[2], ...When iterating through an array using foreach, are there any guaranties that the order in which the elements are returned is the order array[0], array[1], array[2], ...我知道 Array 类现在是这样实现的，但是对框架的未来版本有任何保证吗?同样的问题也适用于 List.I know this is how the Array class is implemented now but are there any guaranties for future versions of the framework? The same questions goes for List<>.推荐答案到目前为止，我不得不不同意所有的答案.I'd have to disagree with all the answers so far.首先，C# 3.0 标准保证了数组上 foreach 的顺序:First, the C# 3.0 standard guarantees the order of foreach on an array:foreach遍历的顺序数组的元素是如下: 对于一维数组元素以递增的方式遍历索引顺序，从索引 0 开始，然后以索引 Length – 1 结尾.对于多维数组，元素是遍历使得索引最右边的维度增加首先，然后是下一个左维度，以此类推. The order in which foreach traverses the elements of an array, is as follows: For single-dimensional arrays elements are traversed in increasing index order, starting with index 0 and ending with index Length – 1. For multi-dimensional arrays, elements are traversed such that the indices of the rightmost dimension are increased first, then the next left dimension, and so on to the left.-- C# 语言规范 3.0 版，第 240 页.-- C# Language Specification Version 3.0, page 240.其次，在对象上，foreach (C#) 和 For Each (VB.NET) 使用对象上的 MoveNext、Reset 和 Current 成员(源).这些通常是 IEnumerator 接口的一部分.Second, on objects, foreach (C#) and For Each (VB.NET) work by using the MoveNext, Reset, and Current members on an object (source). These are typically part of the IEnumerator interface.在具有顺序的集合中(阅读:实现 IList 或 IList(T) 的东西)，这意味着元素将按照后备存储存储它们的顺序返回.In collections that have an order (read: things that implement IList or IList(T)), this means that the elements will be returned in the order that the backing store stores them. 这篇关于在数组、列表等上使用 foreach 时的排序顺序的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！